Help! New TT skipping badly....

Recently bought a used VPI Scout with JMW arm  9 in.  Set up on shelf om my SolidSteel rack where I have always had a TT. Could barely breathe without arm skipping. If I walk anywhere near rack, skips. Floor is carpeted over hardwood, quite solid, never had issue with Clear Audio or Rega table. Took to Audio Connection and had completely gone over and adjusted. Better but still bad. Put cork /sorbathane blocks on shelf and put 3 inch solid maple slab on top of that. No change. removed top shelf and put the cork/ sorb. blocks directly on frame, then maple slab. still skips. everything is dead nuts level, and as stated, floor is firm. Went in basement and put a brace between floor joists, nada. Tomorrow I was thinking of taking rack down and removing spiked feet. Odds this helps? I know some will suggest wall mount, but I don't want to spend anymore money if I can avoid it.As I said, Ive had other TTs in exact spot and you could dance with never a problem. Any input would be greatly appreciated.As I said TT was recently gone over and is set up correctly. Thanks